Sensors, for example, optical, inductive or capacitive sensors, are used in many different technical applications to establish physical or chemical parameters. The purpose of the housing is to protect electronic components on a printed circuit board as well as a sensing element from harmful environmental influences. The electronic components within the housing must be supplied with electrical current. For this reason, it is necessary to route electrical contacts through a housing wall of the housing in order to be able to supply the sensor from the outside with electrical current at an external part of the contact parts of the sensor.
In a fluid-tight version of the sensors, the printed circuit board with the electronic components and the sensing element are, as a rule, encased in a sealing compound. On the one hand, the sealing compound serves to fix the printed circuit board and the sensing element positively and interfacially, and on the other hand to keep out harmful environmental influences, for example, fluids, from the printed circuit board and the sensing element. This means that it is a fluid-tight sensor. Before the sensor is cast in the sealing compound, it is necessary to connect the printed circuit board and the sensing element with the housing, indirectly or directly, in order to position the printed circuit board and/or the sensing element with the help of the sealing compound while the compound is being poured into the inside of the housing. Before the sensor is cast in the sealing compound, the printed circuit board is generally also connected to the electrical contacts of the sensor, generally by means of soldering. In the event of a bonded connection between the printed circuit board and/or the sensing element and the housing before the sensor is cast in the sealing compound, this bonded connection is complex and expensive to produce and has low flexibility for different types of sensors.
DE 195 44 815 C1 discloses a sensor with an electric circuit mounted on a support, which is connected to an electrical connecting element and to a sensing element. Furthermore, it shows a housing with an interior for holding the support, the housing having openings for the connecting element as well as for the sensing element. The sensing element and a first part of the support are embedded in a duroplastic compound. A second part of the support and the electrical connecting element are enveloped by a thermoplastic compound. A seal is located in an intermediate space, adjacent to the opening for the sensing element, between the duroplastic compound and the housing.
DE 100 13 218 C2 discloses a process for the production of a position sensor, with a housing in the interior of which there is an electrical circuit mounted on a support, the process comprises the stages: the support is connected to a connector insert as an electrical connecting element to form a support-connecting element combination in which the connecting element is rigidly connected to the support, the support-connecting element combination is inserted into a housing, which is closed at one measuring end, from a rear end opposite the measuring end, the space around the support-connecting element combination in the interior of the housing is filled with a compound up to a certain level, a cap is connected to the rear end of the housing before the sealing compound has hardened, and the connections of the connecting element are routed through this cap, and the support-connecting element combination is fixed in the housing with this cap.